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Power Electronics
Design:
A Practitioner’s Guide

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Power Electronics
Design:
A Practitioner’s Guide

Keith H. Sueker

AMSTERDAM • BOSTON • HEIDELBERG • LONDON
NEW YORK • OXFORD • PARIS • SAN DIEGO
SAN FRANCISCO • SINGAPORE • SYDNEY • TOKYO
Newnes is an imprint of Elsevier

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Newnes is an imprint of Elsevier
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Support” and then “Obtaining Permissions.”
Tables 14.4 and 14.5 reprinted with permission from IEEE Std. 519-1992–
Recommended Practices and Requirements for Harmonic Control in Electrical
Power Systems, Copyright 1996©, by IEEE. The IEEE disclaims any responsibility
or liability resulting from the placement and use in the described manner.
Recognizing the importance of preserving what has been written,
Elsevier prints its books on acid-free paper whenever possible.
Library of Congress Cataloging-in-Publication Data
Sueker, Keith H.
Power electronics design : a practitioner's guide / by Keith H. Sueker.—1st ed.
p. cm.
Includes bibliographical references and index.
ISBN 0-7506-7927-1 (hardcover : alk. paper) 1. Power electronics—Design
and construction. I. Title.
TK7881.15.S84 2005
621.31'7--dc22
2005013673
British Library Cataloguing-in-Publication Data
A catalogue record for this book is available from the British Library.
ISBN: 0-7506-7946-8
For information on all Newnes publications
visit our website at www.books.elsevier.com

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Contents

List of Figures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi
List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvii
Preface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xix
Chapter 1 Electric Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
1.1
AC versus DC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2
Pivotal Inventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.3
Generation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.4
Electric Traction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.5
Electric Utilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.6
In-Plant Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1.7
Emergency Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Chapter 2 Power Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

2.1
Switchgear. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.2
Surge Suppression. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.3
Conductors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.4
Capacitors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
2.5
Resistors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
2.6
Fuses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
2.7
Supply Voltages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

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vi

2.8
2.9
2.10
2.11
2.12

Contents


Enclosures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
Hipot, Corona, and BIL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
Spacings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
Metal Oxide Varistors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
Protective Relays. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37

Chapter 3 Analytical Tools. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
3.1
Symmetrical Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
3.2
Per Unit Constants. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
3.3
Circuit Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
3.4
Circuit Simulation Notes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
3.5
Simulation Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
Chapter 4 Feedback Control Systems . . . . . . . . . . . . . . . . . . . . .49
4.1
Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
4.2
Amplitude Responses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
4.3
Phase Responses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
4.4
PID Regulators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
4.5
Nested Control Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56
Chapter 5 Transients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
5.1

Line Disturbances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
5.2
Circuit Transients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58
5.3
Electromagnetic Interference . . . . . . . . . . . . . . . . . . . . . . . . . . .61
Chapter 6 Traveling Waves . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65
6.1
Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65
6.2
Transient Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68
6.3
Mitigating Measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71
Chapter 7 Transformers and Reactors . . . . . . . . . . . . . . . . . . . .73
7.1
Transformer Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .74
7.2
Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .78
7.3
Insulation Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .82
7.4
Basic Insulation Level. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .84
7.5
Eddy Current Effects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .85
7.6
Interphase Transformers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .89
7.7
Transformer Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .90
7.8
Reactors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .93


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7.9
7.10
7.11

vii

Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
Instrument Transformers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

Chapter 8 Rotating Machines . . . . . . . . . . . . . . . . . . . . . . . . . .101
8.1
Direct Current Machines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
8.2
Synchronous Machines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
8.3
Induction (Asynchronous) Machines . . . . . . . . . . . . . . . . . . . . 107
8.4
NEMA Designs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
8.5
Frame Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
8.6
Linear Motors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
Chapter 9 Rectifiers and Converters. . . . . . . . . . . . . . . . . . . . .115
9.1

Early Rectifiers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
9.2
Mercury Vapor Rectifiers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
9.3
Silicon Diodes—The Semiconductor Age . . . . . . . . . . . . . . . . 117
9.4
Rectifier Circuits—Single-Phase . . . . . . . . . . . . . . . . . . . . . . . 118
9.5
Rectifier Circuits—Multiphase. . . . . . . . . . . . . . . . . . . . . . . . . 120
9.6
Commutation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Chapter 10 Phase Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . .125
10.1 The SCR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
10.2 Forward Drop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
10.3 SCR Circuits—AC Switches . . . . . . . . . . . . . . . . . . . . . . . . . . 131
10.4 SCR Motor Starters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
10.5 SCR Converters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
10.6 Inversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
10.7 Gate Drive Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
10.8 Power to the Gates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
10.9 SCR Autotapchangers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
10.10 SCR DC Motor Drives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
10.11 SCR AC Motor Drives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
10.12 Cycloconverters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
Chapter 11 Series and Parallel Operation . . . . . . . . . . . . . . . .153
11.1 Voltage Sharing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
11.2 Current Sharing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
11.3 Forced Sharing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160

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viii

Contents

Chapter 12 Pulsed Converters . . . . . . . . . . . . . . . . . . . . . . . . . .163
12.1 Protective Devices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .163
12.2 Transformers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .164
12.3 SCRs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .166
Chapter 13 Switchmode Systems . . . . . . . . . . . . . . . . . . . . . . . .169
13.1 Pulse Width Modulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .169
13.2 Choppers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .173
13.3 Boost Converters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .174
13.4 The “H” Bridge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .175
13.5 High-Frequency Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . .178
13.6 Harmonic Injection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .179
13.7 Series Bridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .180
Chapter 14 Power Factor and Harmonics . . . . . . . . . . . . . . . .181
14.1 Power Factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .181
14.2 Harmonics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .184
14.3 Fourier Transforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .189
14.4 Interactions with the Utility. . . . . . . . . . . . . . . . . . . . . . . . . . . .194
14.5 Telephone Influence Factor. . . . . . . . . . . . . . . . . . . . . . . . . . . .199
14.6 Distortion Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .201
14.7 Zero-Switching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .202
Chapter 15 Thermal Considerations . . . . . . . . . . . . . . . . . . . . .203
15.1 Heat and Heat Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .203
15.2 Air Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .205
15.3 Water Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .206

15.4 Device Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .208
15.5 Semiconductor Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . .213
Chapter 16 Power Electronics Applications . . . . . . . . . . . . . . .215
16.1 Motor Drives and SCR Starters. . . . . . . . . . . . . . . . . . . . . . . . .215
16.2 Glass Industry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .217
16.3 Foundry Operations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .218
16.4 Plasma Arcs and Arc Furnaces . . . . . . . . . . . . . . . . . . . . . . . . .219
16.5 Electrochemical Supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . .219
16.6 Cycloconverters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .220
16.7 Extremely Low-Frequency Communications . . . . . . . . . . . . . .221

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16.8
16.9
16.10
16.11
16.12
16.13
16.14
16.15

ix

Superconducting Magnet Energy Storage . . . . . . . . . . . . . . . . 222
600-kW Opamp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223
Ozone Generators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223

Semiconductor Silicon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224
VAR Compensators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224
Induction Furnace Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
Tokamaks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226
Multi-tap Switching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227

Appendix A

Converter Equations . . . . . . . . . . . . . . . . . . . . . . .229

Appendix B

Lifting Forces . . . . . . . . . . . . . . . . . . . . . . . . . . . . .231

Appendix C

Commutation Notches and THDv . . . . . . . . . . . .233

Appendix D

Capacitor Ratings . . . . . . . . . . . . . . . . . . . . . . . . .235

Appendix E

Rogowski Coils . . . . . . . . . . . . . . . . . . . . . . . . . . . .237

Appendix F

Foreign Technical Words . . . . . . . . . . . . . . . . . . .239


Appendix G

Aqueous Glycol Solutions . . . . . . . . . . . . . . . . . . .241

Appendix H

Harmonic Cancellation with Phase Shifting . . . .243

Appendix I

Neutral Currents with Nonsinusoidal Loads . . . .245

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247

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List of Figures

Figure 1.1
Figure 1.2
Figure 2.1
Figure 2.2
Figure 2.3
Figure 2.4
Figure 2.5
Figure 2.6

Figure 2.7
Figure 3.1
Figure 3.2
Figure 3.3
Figure 4.1
Figure 4.2
Figure 4.3
Figure 4.4
Figure 4.5
Figure 4.6
Figure 4.7
Figure 4.8

Generation systems. .................................................3
Typical section of a utility. ......................................7
Power electronics symbols.....................................16
Typical wire labeling. ............................................22
Stress cone termination for shielded cable.............24
Capacitor construction. ..........................................27
Power resistor types. ..............................................30
Simple corona tester...............................................34
480-V, 60-mm MOV characteristic. ......................36
Symmetrical components.......................................41
Arc heater circuit....................................................44
Circuit voltage and current waveforms..................44
Basic feedback system. ..........................................49
R/C frequency response. ........................................51
Frequency responses of various networks. ............51
Composite response. ..............................................52
Frequency responses, F(s), and corresponding

time responses, f(t).................................................52
Phase responses of an R/C low-pass filter. ............54
Phase lag of a 1.4-ms transport lag. .......................55
PID regulator..........................................................55

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xii

Figure 4.9
Figure 5.1
Figure 5.2
Figure 5.3
Figure 5.4
Figure 5.5
Figure 5.6
Figure 6.1
Figure 6.2
Figure 6.3
Figure 6.4
Figure 6.5
Figure 7.1
Figure 7.2
Figure 7.3
Figure 7.4
Figure 7.5
Figure 7.6

Figure 7.7
Figure 7.8
Figure 7.9
Figure 7.10
Figure 7.11
Figure 7.12
Figure 7.13
Figure 7.14
Figure 7.15
Figure 7.16
Figure 7.17
Figure 7.18
Figure 7.19
Figure 7.20
Figure 7.21
Figure 7.22

List of Figures

Nested control loops. .............................................56
Signal wire routing.................................................59
R/C notch reduction filter. .....................................60
Multiplier input filtering. .......................................61
T-section filter........................................................62
Shunt wiring...........................................................62
Preferred shunt construction. .................................63
Transmission line difference equations. ................67
Transmission line parameters. ...............................67
Transmission line reflections—open load. ............69
Front-of-wave shaping. ..........................................70

Overshoot as a function of rise time. .....................71
Coupled coils. ........................................................74
Ideal transformer....................................................75
Typical transformer representation. .......................76
Transformer regulation phasor diagram.................77
Three-winding transformer. ...................................78
Transformer cross sections. ...................................79
Split bobbin transformer. .......................................83
Surge voltage distribution in a transformer
winding. .................................................................85
Transposition to reduce eddy currents. ..................86
Eddy currents in lamination iron............................86
Eddy current losses in windings. ...........................88
Eddy current heating in shield materials................89
Two- and three-leg interphase transformer
cores. ......................................................................90
Autotransformer connections.................................91
Transformer primary taps. .....................................91
Paralleled transformers. .........................................92
Phase-shifted secondaries, 24-pulse.......................93
Basic equations for an inductive circuit.................94
Inductance of a single-layer solenoid. ...................94
Inductance of a short, fat, multilayer coil. .............95
Inductance of a thin, flat, spiral coil. .....................95
Inductance of a single-layer toroidal coil...............95

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List of Figures


Figure 7.23
Figure 7.24
Figure 7.25
Figure 8.1
Figure 8.2
Figure 8.3
Figure 8.4
Figure 8.5
Figure 8.6
Figure 8.7
Figure 8.8
Figure 8.9
Figure 8.10
Figure 9.1
Figure 9.2

xiii

Elementary iron-core conductor. ...........................96
Three-phase inductance measurement. ..................96
Skirting to improve transformer cooling................98
DC motor characteristics......................................102
DC motor control. ................................................103
Generator phasor diagram....................................104
Generator and motor torque angles......................106
Induction motor equivalent circuit.......................108
Induction motor torque and current. ....................108
Supersynchronous operation................................109
NEMA design torque curves................................111

Induction motor frame types................................111
Elementary rail gun..............................................113
Half-wave rectifier characteristics. ......................118
Full-wave, center-tapped rectifier circuit and
waveforms............................................................120
Figure 9.3
Single-phase bridge (double-way) rectifier and
waveforms............................................................121
Figure 9.4
Three-phase double-wye interphase and bridge
rectifier circuit......................................................121
Figure 9.5
Commutation in a three-phase bridge rectifier. ...123
Figure 10.1 SCR characteristics. .............................................126
Figure 10.2 Typical SCR gate drive........................................127
Figure 10.3 SCR recovery characteristics. ..............................128
Figure 10.4 Equivalent SCR recovery circuit and
difference equations. ............................................129
Figure 10.5 Single-phase SCR AC switch. .............................132
Figure 10.6 SCR single-phase AC switch waveforms. ...........132
Figure 10.7 Three-phase SCR AC switches............................133
Figure 10.8 Three-phase AC switch, 60° phaseback,
0.8 pf lagging load. ..............................................134
Figure 10.9 Three-phase AC switch, 120° phaseback,
0.8 pf lagging load. ..............................................134
Figure 10.10 Starting characteristic of induction motor with
SCR starter. ..........................................................136
Figure 10.11 Speed profile with SCR starter. ...........................137

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List of Figures

Figure 10.12 SCR three-phase bridge converter. ......................138
Figure 10.13 Converter L-N voltages and line currents
(inductive load). ...................................................139
Figure 10.14 Converter bus voltages.........................................139
Figure 10.15 Converter line-to-line voltage. .............................140
Figure 10.16 Converter DC output voltage. ..............................140
Figure 10.17 Converter DC inversion at 150° phaseback. ........141
Figure 10.18 Cosine intercept SCR gate drive. .........................143
Figure 10.19 SCR autotapchanger.............................................146
Figure 10.20 Displacement power factors.................................147
Figure 10.21 Reversing, regenerative SCR DC motor drive.....148
Figure 10.22 SCR current source inverter AC drive. ................149
Figure 10.23 SCR load-commutated inverter AC drive............150
Figure 11.1 High-level gate drive............................................154
Figure 11.2 Series SCR gate drive arrangements....................155
Figure 11.3 Anode-cathode derived gating. ............................156
Figure 11.4 Series SCR recovery characteristics. ...................156
Figure 11.5 Sharing network for series SCRs. ........................157
Figure 11.6 Bus layouts...........................................................158
Figure 11.7 Self and mutual inductances. ...............................159
Figure 11.8 Sharing reactors. ..................................................160
Figure 13.1 Basic pulse width modulation..............................170
Figure 13.2 IGBT schematic and characteristics.....................172
Figure 13.3 Chopper circuit and waveforms. ..........................173

Figure 13.4 Ripple in paralleled choppers...............................174
Figure 13.5 Chopper at 50% duty cycle. .................................175
Figure 13.6 IGBT boost converter. .........................................175
Figure 13.7 “H” bridge............................................................176
Figure 13.8 PWM sine wave switching...................................176
Figure 13.9 IGBT motor drive. ...............................................177
Figure 13.10 Chopper-controlled 30-kHz inverter....................178
Figure 13.11 Harmonic injection...............................................179
Figure 13.12 2400-V, 18-pulse series bridges...........................180
Figure 14.1 Demand multiplier. ..............................................182
Figure 14.2 Power factor correction........................................183
Figure 14.3 Fundamental with third harmonic........................186

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List of Figures

Figure 14.4
Figure 14.5
Figure 14.6
Figure 14.7
Figure 14.8
Figure 14.9
Figure 14.10
Figure 14.11
Figure 14.12
Figure 14.13
Figure 14.14
Figure 14.15

Figure 15.1
Figure 15.2
Figure 15.3
Figure 15.4
Figure 15.5
Figure 15.6
Figure 16.1
Figure 16.2
Figure 16.3
Figure 16.4
Figure 16.5
Figure 16.6
Figure 16.7
Figure 16.8
Figure 16.9
Figure A.1
Figure B.1
Figure C.1
Figure E.1
Figure G.1

xv

SCR DC motor drive waveforms.........................187
SCR DC motor drive characteristics....................188
Transforms in the complex plane.........................189
Transforms of pulses............................................189
Fourier transforms................................................190
Fourier transform for a symmetrical
waveform. ............................................................190

Duty cycle rms value. ..........................................191
Six-pulse and 12-pulse harmonic spectra. ...........194
Harmonic resonance.............................................195
Harmonic trap results...........................................197
High-pass filters. ..................................................198
Current and voltage distortion. ............................199
Fan delivery curves. .............................................206
Basic water cooling system..................................207
Transient thermal impedance curves. ..................211
Thermal network elements...................................212
Composite thermal network.................................213
SCR transient junction temperature rise. .............213
Rod furnace autotapchanger supply.....................218
Typical electrochemical supply. ..........................220
Three-phase cycloconverter. ................................221
ELF transmitter. ...................................................222
600-kW Opamp....................................................223
VAR compensator and control range...................225
Solid-state contactor.............................................226
Autotapchanger performance...............................227
Wide-range, zero-switched tap changer...............228
Single line diagram. .............................................229
Lifting forces and moments. ................................232
Voltage distortion waveform. ..............................233
Rogowski coil construction..................................237
Properties of ethylene and propylene glycol
aqueous mixtures. ................................................242

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List of Tables

Table 2.1
Table 7.1
Table 7.2
Table 7.3
Table 7.4
Table 7.5
Table 10.1
Table 14.1
Table 14.2
Table 14.3
Table 14.4
Table 14.5

Switchgear Electrical Clearance Standards ...............35
Transformer Characteristics.......................................81
Insulation Classes.......................................................82
Air-Core/Iron-Core Inductor Comparisons................93
Self and Mutual Inductances......................................95
Magnetic Units...........................................................97
Converter Equations.................................................142
Energy and Demand.................................................182
Equal Tempered Chromatic Scale ...........................185
Square Wave RMS Synthesis ..................................192
Single-Frequency TIF Values, IEEE 519 ................200

Current Distortion Limits for General
Distribution Systems, IEEE 519 (120 through
69,000 V) .................................................................201
Table 14.6 Zero-Switching Spectra ...........................................202
Table 15.1 Thermal Constants ...................................................204
Table 15.2 Radiation Emissivities of Common Materials .........205
Table F.1 Foreign Technical Words.........................................239

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Preface

I have presented numerous courses in the form of noontime tutorials
during my career with Robicon Corporation. These covered such
essential subjects as transformers, transmission lines, heat transfer,
transients, and semiconductors, to name but a few. The attendees were
design engineers, sales engineers, technicians, and drafters. The tutorials were designed to present an overview of the power electronics
field as well as design information for the engineers. They were very
well received and appreciated. The material was useful to design engineers, but the technicians, drafters, and sales engineers appreciated
the fact that I did not talk over their heads. I have also given tutorials
to national meetings of the IEEE Industrial Applications Society as
well as local presentations. This book represents a consolidation and
organization of this material.
In this book, I have defined power electronics as the application of

high-power semiconductor technology to large motor drives, power
supplies, power conversion equipment, electric utility auxiliaries, and
a host of other applications. It provides an overview of material no
longer taught in most college electrical engineering curricula, and it
contains a wealth of practical design information. It is also intended
as a reference book covering design considerations that are not obvi-

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xx

Preface

ous but are better not learned the hard way. It presents an overview of
the ancillary apparatus associated with power electronics as well as
examples of potential pitfalls in the design process. The book
approaches these matters in a simple, directed fashion with a minimum reliance on calculus. I have tried to put the overall design process into perspective as regards the primary electronic components
and the many associated components that are required for a system.
My intended audience is design engineers, design drafters, and
technicians now working in the power electronics industry. Students
studying in two- and four-year electrical engineering and engineering
technology programs, advanced students seeking a ready reference,
and engineers working in other industries but with a need to know
some essential aspects of power electronics will all find the book both
understandable and useful. Readers of this book will most appreciate
its down-to-earth approach, freedom from jargon and esoteric or nonessential information, the many simple illustrations used to clarify
discussion points, and the vivid examples of costly design goofs.

When I was in graduate school, I was given a copy of The Westinghouse Electrical Transmission and Distribution Reference Manual.
This book covered both theory and practice of the many aspects of the
generation, transmission, and distribution of electric power. For me
and thousands of engineers, it has been an invaluable reference book
for all the years of my work in design. I hope to serve a similar function with this book on power electronics.

Acknowledgments
I have attempted to write about the things I worked with during my 50
years in industry. Part were spent with Westinghouse in magnetic
amplifiers and semiconductors and the last 30 with Robicon Corporation, now ASIRobicon. I had the privilege of working with some very
talented engineers, and this book profits from their experiences as
well as my own. As Engineering Manager of the Power Systems

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Preface

xxi

group at Robicon, I had the best job in the world. My charge was simply to make whatever would work and result in a profit for the company. The understanding was that it would be at least loosely
associated with power semiconductors, although I drifted into a line
of medium-voltage, passive harmonic filters. Yes, we made money on
them. The other aspect of my job was to mentor and work with some
very talented young engineers. Their enthusiasm and hard work actually made me look good. My thanks to Junior, Ken, Pete, Bob, Frank,
Geoff, Frank, Joe, Mark, Joe, Gene, and John. I also owe a debt of
gratitude for the professional associations with Bob, Harry, Dick, and
Pete. I gratefully acknowledge the personnel at SciTech Publishing,
who helped develop the book, and J. K. Eckert & Co., who performed
the editing and layout.

Lastly, I apologize for any errors and omissions and hope the book
will prove useful in spite of them.
Keith H. Sueker, PE
Consulting Engineer
Pittsburgh, PA

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Chapter 1

Electric Power

Relative to the digital age, the electric utility industry may seem old
hat. But power electronics and the power industry have a growing
symbiotic relationship. Nearly all power electronics systems draw
power from the grid, and utility companies benefit from the application of power electronics to motor drives and to converters used for
high-voltage DC transmission lines. The two fields are very much in a
state of constant development of new systems and applications. For
that reason, a short review of the history and the present state of the
electric utility industry is appropriate for consideration by the power
electronics engineer.

1.1. AC versus DC
Take warning! Alternating currents are dangerous. They are fit
only for powering the electric chair. The only similarity between
an a-c and a d-c lighting system is that they both start from the

same coal pile.
And thus did Thomas Edison try to discourage the growing use of
alternating-current electric power that was competing with his DC

1

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2

1

◊ Electric Power

systems. Edison had pioneered the first true central generating station
at Pearl Street, in New York City, with DC. It had the ability to take
generators on and off line and had a battery supply for periods of low
demand. Distribution was at a few hundred volts, and the area served
was confined because of the voltage drop in conductors of a reasonable size. The use of DC at relatively low voltages became a factor
that limited the geographic growth of the electric utilities, but DC was
well suited to local generation, and the use of electric power grew rapidly. Direct current motors gradually replaced steam engines for
power in many industries. An individual machine could be driven by
its own motor instead of having to rely on belting to a line shaft.
Low-speed reciprocating steam engines were the typical prime
movers for the early generators, many being double-expansion
designs in which a high-pressure cylinder exhausted steam to a lowpressure cylinder to improve efficiency. The double-expansion Corliss
engines installed in 1903 for the IRT subway in New York developed
7500 hp at 75 rpm. Generators were driven at a speed higher than the
engine by means of pulleys with rope or leather belts. Storage batteries usually provided excitation for the generators and were themselves

charged from a small generator. DC machines could be paralleled
simply by matching the voltage of the incoming machine to the bus
voltage and then switching it in. Load sharing was adjusted by field
control.
Alternating-current generators had been built for some years, but
further use of AC power had been limited by the lack of a suitable AC
motor. Low-frequency AC could be used on commutator motors that
were basically DC machines, but attempts to operate them on the
higher AC frequencies required to minimize lamp flicker were not
successful. Furthermore, early AC generators could be paralleled only
with difficulty, so each generator had to be connected to an assigned
load and be on line at all times. Battery backup or battery supply at
light load could not be used. Figure 1.1 shows the difference. Finally,
generation and utilization voltages were similar to those with DC, so
AC offered no advantage in this regard.

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1.2.

Pivotal Inventions

FIGURE 1.1

3

Generation systems.

1.2. Pivotal Inventions

Two key inventions then tipped the scales toward AC and initiated
Edison’s famous statement that opens this chapter. The first of these
was the transformer. George Westinghouse acquired the patent rights
from Gaulard and Gibbs for practical transformers. They allowed AC
power to be transmitted at high voltages, then transformed to serve
low-voltage loads. Power could now be transmitted with low losses
yet be utilized at safe voltages, and this meant power could be generated at locations remote from the load. Hydroelectric generation could
supply industries and households far from the dam. An early installation of AC generation and distribution was made by William Stanley,
a Westinghouse expert, in Great Barrington, MA, in 1886. Distribution was at 500 V, and the Siemens generator, imported from London,
supplied two transformers connected to some 200 lamps throughout
the town.
The second invention was that of the induction motor, the result of
research by a brilliant young engineer, Nikola Tesla, employed by
Westinghouse. The first designs were for two-phase power, although
three-phase designs soon followed. Three-phase transmission was
preferred, because it minimized the amount of copper required to
transmit a given amount of power. The simple, rugged induction
motor was quickly put into production and was the key to utilizing AC

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